Update:Vanity Fair cultural opiner James Wolcott calls Parker and Stone "the most unlikely Rodgers and Hammerstein team ever to bowl a thundering strike." But from the way he describes their show, it sounds about as far from elephant-eye-high-corny-Americana as it's possible to get:

I’ve never heard such roof-shaking laughter in a Broadway theater—not even during the riotous crescendos of Michael Frayn’s farce Noises Off—as I heard in the second-act “Spooky Mormon Hell Dream” extravaganza, where Johnnie Cochran and Hitler boogaloo amid the licking flames. Unhingingly burlesque, The Book of Mormon resembles a farrago the director Ken Russell would have hurled if his sense of humor didn’t have thick hooves—a cheerful travesty of religious zeal, liberal pieties, cultural slumming, and warlord machismo with enough projectile f-bombing to make David Mamet cash in his poker chips and concede defeat. What makes the show so winningly wholesome as shock therapy is the sharp contrast of those young missionary men in their glee-chorus zeal running smack into an African Tobacco Road of poverty, tribal strife, and rampant disease, with the show turning it into an ironic “teaching moment” for both sides. Their crisp white shirts and bright smiles arrayed in a singing-dancing row are the virgin tapestry of an American innocence that remains impervious no matter how many times it’s buggered by brute reality (here, literally, as an X-ray reveals a Mormon Bible rammed southward by a local guerrilla leader practicing proctology without a license). No cut-and-paste pastiche, The Book of Mormon honors its theatrical forebears, mating cartoon absurdism and Broadway classicism—the plagued village’s enactment of the story of Joseph Smith and Brigham Young performed as a musical-within-a-musical, like Jerome Robbins’s staging of Uncle Tom’s Cabin in The King and I, with Taymor-esque brown ribbons simulating diarrhea flying aft and invocations of the “magic fuck frog,” a phrase that brought great amusement to Kate Winslet, seated in front of us.